The application proposes to renew a Specialized Center of Research (SCOR) in the Molecular Genetics of Hypertension in the University of Iowa Cardiovascular Center. The overall theme is "Molecular and Physiologic Mechanisms of Genetic Hypertension in Humans and Experimental Animals." This initiative, which we have been planning for the past 18 months to fund 6 projects and one scientific core. The center brings together a cadre of investigators including outstanding molecular geneticists (Val Sheffield, Bento Soares and Curt Sigmund at Iowa and John Rapp in Ohio); molecular biologists (Peter Snyder and John Engelhardt); a genetic epidemiologist and biostatistician (Trudy Burns); and leading hypertension physiologists (Allyn Mark, John Stokes, Robin Davisson, Gerald DiBona, and Joseph Hill) to pursue the three broad goals of the Hypertension Molecular Genetics SCOR. The strengths of the proposal include: (1) study of two distinctive human populations including nuclear families from the Muscatine population study of obesity and blood pressure; and Bedouin families from a homogenous population in Southern Israel with a high incidence of obesity; (2) a leading human and rat molecular genetics laboratory with capability for high throughput gene identification, sequencing of cDNAs, and generation and analysis of cDNA microarrays; (3) coordinated pursuit of chromosomal quantitative trait loci, physiologic and cellular intermediate phenotypes, and candidate genes in rat models of genetically salt-sensitive hypertension; (4) pursuit of functional data on the consequences of genetic variation in genes encoding the epithelial sodium channel; and (5) use of transgenic mice, tissue-specific knockout mice and mutant mouse strains to test the role of tissue-specific renin- angiotensin systems in hypertension and cardiac hypertrophy, and to study fundamental mechanisms in obesity-induced hypertension. These investigators have established vibrant collaborations within our SCOR and with investigators studying the genetics of hypertension at other institutions. This coalition of leading molecular geneticists and hypertension physiologists in the Iowa SCOR holds promise for continued substantial contribution to advancing knowledge of the molecular genetics of hypertension.